In Patent Literature 1 and Patent Literature 2, catalyst-aided chemical processing methods are disclosed. Catalyst-aided chemical processing methods include using a catalyst made of a transition metal on a processing reference surface, placing a workpiece in a solution that does not contain abrasive grains or the like, bringing the processing reference surface into contact with or proximal to the processed surface of the workpiece, causing the processing reference surface and the processed surface to move relative to each other, producing compounds in a chemical reaction between active species generated from the solution and surface atoms of the workpiece, and removing the compounds to process (etch) the workpiece; it is thereby possible perform planarization processing of a surface of difficult-to-process substrates made, for example, of SiC and GaN with high precision approximately at an atomic level.
Incidentally, as a device that planarizes by reciprocally moving the surface (processed surface) of the pad, which is formed of a transition metal layer that serves as the catalyst layer, and the surface of the processed substrate (processed surface), which serves as the workpiece, a large-diameter circular pad is rotated on a platen, and is brought into contact or proximity with the surface of the processed substrate, which has a smaller diameter and is held by a rotating holder, as shown conventionally in Patent Literature 1.